The Design Of Cylinder Boring Machine About Steam Turbine Low Pressure Cylinder And Research Of Main Structure

The steam turbine equipment is huge.The low pressure cylinder is a key component in a steam turbine.There are dehumidification ring grooves in the cylinder internal.The diameter of the grooves will be increased in order to meet the needs of the power plant unit capacity But considering the transformation period,the efficiency and economy of power plant and other factors,the low pressure cylinder ring groove need to be processed at the scene of the power plant.However,the traditional processing equipment is hard on the unit.Its processing range can not meet the requirements.Therefore,it needs to design specifically targeted equipment--cylinder boring machine.This paper researched the overall design for cylinder boring machine,and using simulation research and model experiment to study the structure performance of cylinder boring machine.The details are as follows:First of all,the overall design of the cylinder boring machine.In this article the axial dimensions of the low pressure cylinder is 6.57 m and turning radius is 1.9m.And for horizontal structures.The weight of the tool post will have a strong impact for horizontal cutting.Cycloid reducer is characterized by relatively large deceleration,stable and reliable rotation,strong bearing capacity and impact resistance,etc.So boring machine with three-phase asynchronous motor and cycloid reducer as a power input.Application of electrical control motor to achieve a variety of boring machine actionSecondly,in order to the minimize impact load on the spindle,using software ADMAS for the simulation of the spindle,that the two tool holders are in nine different angles.Considering the quality of the tool post and the spindle,the force and moment of the main shaft are sinusoidal and cyclical.So the impact load on the spindle is minimal,when the phase is the largest and the force and torque on the spindle are minimal.According to this situation select the two knife angle of 180°.According to the applied cutting speed and cutting force,the simulation results show that the output shaft speed of the motor reducer is 10.95 r/min and the torque is 7.82 Nm.The results are in the range and will not produce overload.Thirdly,simulation analysis of the key parts of the cylinder boring machine.The structure and weight of the turret and spindle of the boring machine is an important factor,which can affect the processing precision and quality of the desiccant ring groove.Therefore,according to the dimensions of the turret and the spindle,ANSYS is used to establish four finite element models of the tool holder and the tool holder-spindle,respectively.Analyzing the statistically to determine the stiffness and strength of the tool holder.To the light weight of the premise,wedgeshaped cross-section of the knife(d)is the optimal structure.On this basis,the structure of the tool holder(d)is also optimal in the modal analysis.The overall modal analysis verifies the rationality of the matching between the tool holder and the spindle and the twelfth order natural frequencies and modes are obtained.The frequency is closer to 0 Hz,the larger the amplitude.When the frequency is more than 0.2Hz,it will enter the stable cutting state and will not occur resonance phenomenon.This will provide a theoretical reference for avoiding resonance in the work.Finally,in order to improve the reliability of the theoretical analysis data,the key components of the boring machine will be experimentally analyzed.The stiffness,strength and modal characteristics of the tool holder were analyzed.The reliability of the experimental data and the results was verified by the software of the experimental system and curve fitting.And the parameters such as the natural frequency and the mode shape are obtained.The experiment and the simulation analysis are verified by the linear fitting and comparison of the experimental value and the theoretical value.The same experiment method was used to verify the whole machine.Experimental results show that the strength and stiffness of the experimental and theoretical values are basically the same.The experimental results of modal analysis are within the allowable error range.